Seat rail assembly

ABSTRACT

A seat rail assembly capable of stably holding a position of one or more vehicle seats relative to the vehicle floor. The seat rail assembly includes an upper rail on which the seat is provided and a lower rail which is mounted to the vehicle floor. The upper rail is slidably provided within the lower rail, and incorporates an engagement assembly with a dual wedge engagement assembly to ensure constant contact between the lower and upper rails. A gearbox configured to remove lash may be provided on the upper rail for moving the upper rail relative to the lower rail.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/762,789 filed on Mar. 23, 2022, which is the U.S. National Stageentry of International Application No. PCT/IB2021/000755 filed under thePatent Cooperation Treaty on Nov. 1, 2021, which claims priority to andthe benefit of U.S. Provisional Patent Application No. 63/107,811 filed30 Oct. 2020, U.S. Provisional Patent Application No. 63/107,822 filed30 Oct. 2020, and U.S. Provisional Patent Application No. 63/107,840filed 30 Oct. 2020, all of which are incorporated by reference herein intheir entirety.

BACKGROUND

Seat rail assemblies are incorporated into vehicles for movably mountingpassenger seats to the vehicle floor. Seat rail assemblies typicallyinclude a lower rail mounted to a floor and an upper rail on which thepassenger seat is mounted. The upper rail is slideably connected to thelower rail such that the passenger seat may slide forward or rearward.Operation of the vehicle, however, may result in vibration that istransmitted into the seat rail assembly and thereby result in rattlingbetween the lower and upper rails. Moreover, manufacture of the lowerand upper rails, especially in the case of manufacturing longer rails,may result in variation or undulation along the length of the rail. Suchvariation and undulation may make it difficult for existing assembliesto maintain constant contact between the lower and upper rails whenencountering such variation or undulation, which may also result inrattling. This rattling is undesirable and may even constituteunacceptable performance.

To inhibit such rattling, existing seat rail assemblies may incorporateslider assemblies which couple the upper rail to the lower rail.Existing slider assemblies, however, may result in too much or toolittle sliding resistance or uneven sliding resistance when slidingforward and/or rearward. To effectuate proper sliding resistance,existing slider assemblies do not maintain constant contact between thelower and upper rails, which may nevertheless result in undesirablerattling. Accordingly, an improved seat slide assembly is needed.

SUMMARY

Disclosed herein is a seat rail assembly for mounting a vehicle seat. Insome embodiments, the seat rail assembly comprises a lower railconfigured to be mounted to a vehicle floor, the lower rail defining asliding space; an upper rail configured to receive a vehicle seatmounted thereon, the upper rail at least partially provided within thesliding space of the lower rail and slidable relative to the lower railin a first direction or in a second direction opposite the firstdirection; an engagement assembly provided within the sliding space ofthe lower rail, the engagement assembly comprising a lower engagementmember and an upper engagement member that are configured to moveindependently of each other depending on movement of the upper railrelative to the lower rail, the lower engagement member slidablyprovided on the upper rail, the upper engagement member slidablyprovided on the lower engagement member and slidable between a firstposition and a second position; wherein the lower engagement member isbiased in the first direction and the upper engagement member is biasedin the second direction towards the first position; and wherein, as theupper rail slides in the first and second directions relative to thelower rail, the upper engagement member maintains contact with the lowerrail and the lower engagement member maintains contact with the upperrail.

In further embodiments, a surface of the upper engagement membermaintains contact with a surface of the lower rail and a surface of thelower engagement member maintains contact with a surface of the upperrail. In even further embodiments, the surface of the upper rail is aninclined surface, and the lower engagement member is slidably providedon the inclined surface. In other further embodiments, the surface ofthe upper engagement member is a side surface of the upper engagementmember, and the surface of the lower engagement member is a side surfaceof the lower engagement member. In other further embodiments, thesurface of the upper engagement member is an upper surface of the upperengagement member, and the surface of the lower engagement member is alower surface of the lower engagement member. In other furtherembodiments, the surface of the lower rail is an interior surface of thelower rail, and the surface of the upper rail is an exterior surface ofthe upper rail. In other further embodiments, the surface of the lowerrail is an exterior surface of the lower rail, and the surface of theupper rail is an interior surface of the upper rail. In even furtherembodiments, the upper surface of the upper engagement member maintainscontact with an interior surface of the lower rail and the lower surfaceof the lower engagement member maintains contact with a surface of theupper rail. In some embodiments, a track is formed on the lowerengagement member, and wherein the upper engagement member is configuredto engage the track when sliding on the lower engagement member. In evenfurther embodiments, the track has a slope of opposite sign than a slopeof an inclined surface of the upper rail, and in even furtherembodiments, the slope of the track and the slope of the inclinedsurface are of the same magnitude. In some embodiments, a height of theengagement assembly measured between the upper surface of the upperengagement member and the lower surface of the lower engagement memberis greatest when the upper engagement member is in the first position.In some embodiments, the lower engagement member is biased in the firstdirection via an extension spring, and in even further embodiments, afirst end of the extension spring is attached to the upper rail and asecond end of the extension spring is attached to the lower engagementmember. In some embodiments, the upper engagement member is biased inthe second direction via a torsion spring, and in even furtherembodiments, a first end of the torsion spring is attached to the upperengagement member and a second end of the torsion spring is attached tothe lower engagement member. In even further embodiments, the torsionspring inhibits travel of the upper engagement member on the lowerengagement member beyond the second position. In some embodiments, thelower engagement member includes a stop that inhibits travel of theupper engagement member on the lower engagement member beyond the secondposition. In some embodiments, the lower engagement member includes astop that inhibits travel of the upper engagement member on the lowerengagement member beyond the first position.

In some embodiments, the upper rail has a first end and a second endopposite the first end, and wherein the engagement assembly includes afirst and second engagement assembly, the first engagement assemblybeing provided within the sliding space of the lower rail proximate tothe first end of the upper rail and the second engagement assembly beingprovided within the sliding space of the lower rail proximate to thesecond end of the upper rail, and wherein the lower engagement member ofthe first engagement assembly maintains contact with a first surface ofthe upper rail and the lower engagement member of the second engagementassembly maintains contact with a second surface of the upper rail. Infurther embodiments, the first surface of the upper rail is a firstinclined surface and the second surface of the upper rail is a secondinclined surface, and the lower engagement member of the firstengagement assembly is slidably provided on the first inclined surfaceand the lower engagement member of the second engagement assembly isslidably provided on the second inclined surface. In even furtherembodiments, the first inclined surface has a slope of opposite signthan a slope of the second inclined surface, and in even furtherembodiments, the slope of the first inclined surface and the slope ofthe second inclined surface are of the same magnitude.

In some embodiments, the seat rail assembly further comprises a memberfor controlling lateral displacement of the upper rail and the lowerrail relative to each other. In some of these embodiments, the member issupported by the upper rail. In even further embodiments, the membermaintains contact with both the upper rail and the lower rail, and insome embodiments, the member comprises one or more ribs that abut thelower rail.

Embodiments herein are also directed towards a seat rail assemblycomprising: a first rail configured to be mounted to a vehicle floor,the first rail defining a sliding space; a second rail configured toreceive a vehicle seat mounted thereon, the second rail at leastpartially provided within the sliding space of the first rail andslidable relative to the first rail in a first direction or in a seconddirection opposite the first direction; an engagement assembly providedbetween the first rail and the second rail, the engagement assemblycomprising a first surface and a second surface that are configured tomove independently of each other depending on movement of the secondrail relative to the first rail, the first surface slidably provided ona slide surface of the second rail, the second surface slidable betweena first position and a second position; wherein the first surface of theengagement assembly is biased in the first direction and the secondsurface of the engagement assembly is biased in the second directiontowards the first position; wherein, as the second rail slides relativeto the first rail, the second surface of the engagement assemblymaintains contact with an interior surface of the first rail and thefirst surface of the engagement assembly maintains contact with theslide surface of the second rail; and wherein a height of the engagementassembly measured between the second surface of the engagement assemblyand the first surface of the engagement assembly is greatest when thesecond surface of the engagement assembly is in the first extremeposition. In some embodiments, the slide surface of the second rail isan inclined surface, and the first surface of the engagement assembly isslidably provided on the inclined surface. In some embodiments, theengagement assembly further comprises a first engagement member and asecond engagement member, and wherein the first surface of theengagement assembly is a surface of the first engagement member and thesecond surface of the engagement assembly is a surface of the secondengagement member.

Embodiments herein are also directed towards a seat rail assembly formounting a vehicle seat to a vehicle floor, comprising: a first railconfigured to be mounted to a vehicle floor, the first rail defining asliding space; a second rail configured to receive a vehicle seatmounted thereon, the second rail at least partially provided within thesliding space of the first rail and slidable relative to the first railin a first direction or in a second direction opposite the firstdirection, the second rail having a first end and a second end whichcorrespond with the first direction and the second direction,respectively; a first engagement assembly and a second engagementassembly each provided between the first rail and the second rail, thefirst engagement assembly positioned proximate the first end of thesecond rail and the second engagement assembly positioned proximate thesecond end of the second rail, the first and second engagement assemblyeach comprising a first engagement member and an second engagementmember that are configured to move independently of each other dependingon movement of the second rail relative to the lower rail, the firstengagement member slidably provided on the second rail, the secondengagement member slidably provided on the first engagement member andslidable between a first position and a second position; wherein, as thesecond rail slides relative to the first rail, the second engagementmember maintains contact with the first rail and the first engagementmember maintains contact with the second rail. In some embodiments, thefirst engagement member of the first engagement assembly is biased inthe first direction and the second engagement member of the firstengagement assembly is biased in the second direction towards the firstposition, and wherein the first engagement member of the secondengagement assembly is biased in the second direction and the secondengagement member of the second engagement assembly is biased in thefirst direction towards the first position. In some embodiments, thefirst engagement member of the first engagement assembly is biased inthe first direction and the second engagement member of the firstengagement assembly is biased in the second direction towards the firstposition, and wherein the first engagement member of the secondengagement assembly is biased in the first direction and the secondengagement member of the second engagement assembly is biased in thesecond direction towards the first position.

Embodiments herein are also directed towards mounting assembly formounting a vehicle seat to a vehicle floor. In such embodiments, themounting assembly may comprise a first seat rail assembly as variouslydescribed above, and a second seat rail assembly as variously describedabove.

Embodiments herein are also directed towards a method of assembling avehicle seat rail assembly. The method may comprise providing a firstrail having a slide surface, the first rail have a first end and asecond end opposite the first end; providing a first engagement memberon the slide surface of the first rail, the first engagement memberhaving first surface that abuts on and is slidable on the slide surfaceof the first rail, connecting the first engagement member to the firstrail with a first spring such that the first engagement member is biasedtowards the first end; providing a second engagement member on a secondsurface of the first engagement member, the second engagement memberhaving first surface that abuts on and is slidable on the second surfaceof the first engagement member, and connecting the second engagementmember to the first engagement member or the first rail with a secondspring such that the second engagement member is biased towards thesecond end. In some embodiments, the method further comprises installingthe first rail into a second rail, wherein the second rail has a slidesurface, and wherein the second engagement member has a second surfacethat abuts on and is slidable on the slide surface of the second rail.In further embodiments, as the first rail slides in a first directionand opposite second direction relative to the second rail, the secondengagement member maintains contact with the second rail and the firstengagement member maintains contact with the first rail; and in evenfurther embodiments, the method further comprises mounting the secondrail to a floor of a vehicle and/or mounting a vehicle seat to the firstrail.

Embodiments herein are also directed towards a method of assembling aseat rail assembly. The method may comprise providing lower rail whichdefines a sliding space; providing an upper rail at least partiallywithin the sliding space of the lower rail and slidable relative to thelower rail in a first direction or in a second direction opposite thefirst direction; and installing an engagement assembly between the lowerrail and the upper rail, the engagement assembly comprising a lowerengagement member and an upper engagement member that are configured tomove independently of each other depending on movement of the upper railrelative to the lower rail, the lower engagement member slidablyprovided on the upper rail, the upper engagement member slidablyprovided on the lower engagement member and slidable between a firstposition and a second position, wherein the lower engagement member isbiased in the first direction and the upper engagement member is biasedin the second direction towards the first extreme position, and wherein,as the upper rail slides in the first and second directions relative tothe lower rail, the upper engagement member maintains contact with thelower rail and the lower engagement member maintains contact with theupper rail. In some embodiments, an upper surface of the upperengagement member maintains contact with an interior surface of thelower rail and a lower surface of the lower engagement member maintainscontact with a surface of the upper rail. In further embodiments, thesurface of the upper rail is an inclined surface, and the lowerengagement member is slidably provided on the inclined surface. In someembodiments, the method further comprises mounting the lower rail to afloor of a vehicle and/or mounting a vehicle seat to the upper rail.

The present disclosure is also directed towards a seat rail assemblycomprising a first rail having longitudinally spaced slots; and a secondrail having a gear box. In these embodiments, the gear box may compriseat least one drive screw rotatable in a first or second rotationaldirection, each drive screw having a shaft and a thread configured toengage with the longitudinally spaced slots of the first rail; a lobeprovided on the shaft of the drive screw proximate an end of the threadand configured to engage with the longitudinally spaced slots of thefirst rail, wherein the lobe is freely rotatable relative to the threadof the drive screw; and a lobe spring configured to bias the lobe in thefirst rotational direction. In some embodiments, the first rail definesa sliding space between the longitudinally spaced slots. In even furtherembodiments, the second rail is at least partially providing within thesliding space of the first rail. In some embodiments, the lobe has alimited range of rotation about the shaft. In some embodiments, the lobeincludes a thread that is continuous with the thread of the drive screw.In some embodiments, the lobe includes a thread, and the thread of thelobe and the thread of the drive screw have an equal pitch. In someembodiments, the lobe has a bore within which the shaft of the drivescrew is received, the shaft of the drive screw includes a flat feature,and a pair of angled flat surfaces are formed in the bore of the lobeand wherein the lobe is rotatable relative to the shaft between a firstposition, where a first of the pair of angled flat surfaces abuts theflat feature, and a second position, where a second of the pair ofangled flat surfaces abuts the flat feature.

In some embodiments, the second rail includes a second gear box. Inthese embodiments, the second gear box may comprise at least one drivescrew rotatable in a first or second rotational direction, each drivescrew having a shaft and a thread configured to engage with thelongitudinally spaced slots of the first rail; a lobe provided on theshaft of the drive screw proximate an end of the thread and configuredto engage with the longitudinally spaced slots of the first rail,wherein the lobe is freely rotatable relative to the thread of the drivescrew; and a lobe spring configured to bias the lobe in the firstrotational direction.

Embodiments herein are also directed towards a gear box for a railassembly. The gear box may comprise at least one drive screw rotatablein a first or second rotational direction, each drive screw having ashaft and a thread configured to engage with longitudinally spaced slotsof a rail; a lobe provided on the shaft of the drive screw proximate anend of the thread and configured to engage with the longitudinallyspaced slots of the rail, wherein the lobe is freely rotatable relativeto the thread of the drive screw; and a lobe spring configured to biasthe lobe in the first rotational direction. In some embodiments, therail defines a sliding space between the longitudinally spaced slots. Insome embodiments, the gear box is at least partially providing withinthe sliding space of the rail. In some embodiments, the lobe has alimited range of rotation about the shaft. In some embodiments, the lobeincludes a thread that is continuous with the thread of the drive screw.In some embodiments, the lobe includes a thread, and the thread of thelobe and the thread of the drive screw have an equal pitch. In someembodiments, the lobe has a bore within which the shaft of the drivescrew is received, the shaft of the drive screw includes a flat feature,and a pair of angled flat surfaces are formed in the bore of the lobeand wherein the lobe is rotatable relative to the shaft between a firstposition, where a first of the pair of angled flat surfaces abuts theflat feature, and a second position, where a second of the pair ofangled flat surfaces abuts the flat feature.

Embodiments herein are also directed towards a seat rail assembly formounting a vehicle seat to a vehicle floor. The seat rail assembly maycomprise a first rail configured to be mounted to a vehicle floor, thelower first rail having longitudinally spaced slots and defining asliding space; a second rail configured to receive a vehicle seatmounted thereon, the second rail at least partially provided within thesliding space of the first rail and slidable relative to the lower railin a first direction or in a second direction opposite the firstdirection; and a gear box provided on the second rail. In theseembodiments, the gear box may comprise at least one drive screwrotatable in a first or second rotational direction, each drive screwhaving a shaft and a thread configured to engage with the longitudinallyspaced slots of the first rail, a lobe provided on the shaft of thedrive screw proximate an end of the thread and configured to engage withthe longitudinally spaced slots of the first rail, wherein the lobe isfreely rotatable relative to the thread of the drive screw, and a lobespring configured to bias the lobe in the first rotational direction.Also in these embodiments, the seat rail assembly may comprise anengagement assembly provided within the sliding space of the first rail,the engagement assembly comprising a first engagement member and asecond engagement member that are configured to move independently ofeach other depending on movement of the second rail relative to thefirst rail, the first engagement member slidably provided on the secondrail, the second engagement member slidably provided on the firstengagement member and slidable between a first position and a secondposition; wherein the first engagement member is biased in the firstdirection and the second engagement member is biased in the seconddirection towards the first position; and wherein, as the second railslides relative to the first rail in response to operation of the gearbox, the second engagement member maintains contact with the first railand the first engagement member maintains contact with the second rail.

Embodiments herein are also directed towards a seat rail assembly formounting a vehicle seat to a vehicle floor. The seat rail assembly maycomprise a first rail configured to be mounted to a vehicle floor, thefirst rail defining a sliding space; a second rail configured to receivea vehicle seat mounted thereon, the second rail at least partiallyprovided within the sliding space of the first rail and slidablerelative to the first rail in a first direction or in a second directionopposite the first direction; an engagement assembly provided betweenthe first rail and the second rail, the engagement assembly slidablyprovided on an inclined surface of the second rail; a linear biasingmember connecting the engagement assembly to the second rail such thatthe engagement member is biased along the inclined surface of the secondrail towards a first position; wherein, as the second rail slidesrelative to the first rail, the engagement assembly maintains contactwith both an interior surface of the first rail and the inclined surfaceof the second rail.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures are included to illustrate certain aspects of thepresent disclosure, and should not be viewed as exclusive embodiments.The subject matter disclosed is capable of considerable modifications,alterations, combinations, and equivalents in form and function, withoutdeparting from the scope of this disclosure.

FIG. 1 is an isometric view of an example seat rail assembly accordingto one or more embodiments of the present disclosure.

FIG. 2 is cross-sectional end view of the seat slide of FIG. 1 .

FIG. 3 is cross-sectional side view of the seat slide of FIG. 1 .

FIG. 4 is cross-sectional top view of the seat slide of FIG. 1 .

FIGS. 5A and 5B are views of the lower and upper rails, respectively.

FIGS. 6A and 6B are side views of the engagement assembly of FIG. 3 .

FIGS. 7A and 7B are partial side views of the engagement assemblydepicting example operation.

FIGS. 8A and 8B illustrate an example interaction of the engagementassemblies and the upper rail.

FIGS. 9A and 9B illustrate an example relative movement of the lower andupper engagement members.

FIGS. 10A and 10B illustrate an alternate example interaction of theengagement assemblies on the upper rail.

FIGS. 11A and 11B illustrate an example noise-reducing lateral controlfeature that may be integrated on the lower rail in some embodiments.

FIG. 12 illustrates an example installation of the lateral controlfeatures in an end of the upper rail.

FIG. 13 is a side view of an alternate engagement assembly.

FIGS. 14A and 14B illustrate another alternate engagement assembly.

FIGS. 15A-15D illustrate variations of the engagement assembly of FIG.14 .

FIGS. 16A-16C is another alternate engagement assembly.

FIG. 17 illustrates an alternate cam engagement assembly, according toone or more alternate embodiments.

FIG. 18 illustrates an example operation of the engagement assembly ofFIG. 15B.

FIG. 19 illustrates another alternate engagement assembly.

FIG. 20 illustrates a gearbox utilizable to drive the seat rail assemblydescribed herein.

FIG. 21 illustrates a partial exploded view of the gearbox of FIG. 20 .

FIG. 22 illustrates an example operation of the gearbox's drive train.

FIG. 23 is an end view of the drive chain of FIG. 22 .

FIGS. 24A and 24B illustrate example operation of non-spring loaded(inactive) lobe and a spring loaded (active) lobe, respectively, in aseat rail assembly.

FIG. 25 illustrates an example drive screw configured to limit rotationof the lobe.

FIGS. 26A and 26B illustrate example operation of the gearbox's drivetrain to eliminate slop in the system.

FIGS. 27A and 27B illustrate example operation of the gearbox's drivetrain to eliminate slop in the system.

FIGS. 28A and 28B illustrate an example of the lobe 2004, according toone or more embodiments of the present disclosure.

FIG. 29 illustrates an alternate gearbox utilizable to drive the seatrail assembly described herein.

FIG. 30 is a side cross-sectional view of the gearbox of FIG. 29 .

FIG. 31 illustrates a partial exploded view of the gearbox of FIG. 30 .

FIG. 32 illustrates an example operation of the gearbox's drive train ofFIG. 31 .

FIG. 33 is a partial cross-sectional view illustrating example operationof the gearbox of FIG. 29 .

FIGS. 34A-34B and 35A-35B illustrate example operation of drive trainwithin the gearbox 2900 to eliminate slop in the system.

DETAILED DESCRIPTION

The present disclosure is related to seat rail assemblies and, moreparticularly, to seat rail assemblies that support the position of avehicle seat and permit easy maneuvering of the seat without rattling orundesired resistance.

FIG. 1 is an isometric view of an example seat rail assembly 100according to one or more embodiments of the present disclosure. FIG. 2is a cross-sectional end view of the seat rail assembly 100 of FIG. 1 .FIG. 3 is cross-sectional side view of the seat rail assembly 100 ofFIG. 1 . FIG. 4 is cross-sectional top view of the seat rail assembly100 of FIG. 1 . The seat rail assembly 100 is just one example of a seatrail assembly that incorporates the principles of the presentdisclosure. Many alternative designs and configurations of the seat railassembly 100 may be employed, without departing from the scope of thisdisclosure. The seat rail assembly 100 supports at least one vehicleseat (not illustrated) on a vehicle floor (not illustrated) in a mannerpermitting movement of the vehicle seat relative to the floor. Also, itshould be appreciated that two (or more) of the seat rail assemblies 100may be utilized to support a vehicle seat's left and right hand side(and possible middle region). For purposes of simplicity, one seat railassembly 100 is illustrated and described, but it should be appreciatedthat any number of seat rail assemblies 100 may be utilized withoutdeparting from the present disclosure. Also, while the seat railassembly 100 is described herein with regard to mounting a vehicle seat(or more than one seat) relative to a floor of a vehicle, the seat railassembly 100 may be utilized to mount the vehicle seat to anothersurface of the vehicle, such as a ceiling or a sidewall. In addition,while the present subject matter is disclosed as a rail assembly formovably mounting a vehicle seat to a surface of a vehicle, the seat railassembly 100 may be utilized to movably mount other objects relative tothe vehicle surface, such as an ottoman, table, bench, entertainmentequipment, etc. Moreover, while the seat rail assembly 100 is describedas being utilized in automobile and vehicle applications, the presentsubject matter may be utilizable in other various other non-automotiveapplications where it is desirable to inhibit rattling between movablecomponents. All such applications are considered within the scope of thepresent disclosure.

The seat rail assembly 100 includes a lower rail 102 and an upper rail104. The lower rail 102 defines an internal cavity or sliding space 106within which the upper rail 104 is slidingly provided. The upper rail104 may slide relative to the lower rail 102 with or without an externalsource of power as described herein. Thus, the upper rail 104 isslidable relative to the lower rail 102 with either powered or unpoweredmovement. In this manner, the upper rail 104 is slidingly provided onthe lower rail 102 such that the upper rail 104 may move (or slide)forward or rearward as indicated by the arrow X (i.e., the upper rail104 may slide in a forward direction or an opposite rearward direction).For example, when installed in a vehicle, the lower rail 102 extends inthe X direction, which is the vehicle seat's front and/or reardirection, and has a width in a Y direction. As described herein, thelower rail 102 may be mounted (i.e., placed or fixed in position) on avehicle floor. Similarly, the vehicle seat may be mounted (i.e., placedor fixed in position) on the upper rail 104 as described herein.

FIG. 5A illustrates a cross-sectional end view of the lower rail 102.FIG. 5B illustrates a partial perspective view of an end of the upperrail 104. The lower rail 102 has a bottom plate section 108, a pair ofouter plate sections 110 extending upward from both right and left endsof the bottom plate section 108, upper plate sections 112 extending fromupper ends of the right and left outer plate sections 110 to the insidein right-left direction Y, and inner plate sections 114 extendingdownward from inner ends of the right and left upper plate sections 112.

The lower rail 102 defines a sliding space 106. The sliding space 106 isa compartment within which at least a portion of the upper rail 104 maybe received and slide within. The sliding space 106 is surrounded by thebottom plate section 108, the right and left outer plate sections 110,the right and left upper plate sections 112, and the right and leftinner plate sections 114. The sliding space 106 receives a lower portionof the upper rail 104. The sliding space 106 opens upward from a spacebetween the right and left inner plate sections 114. The upper rail 104is mounted such that an upper section 116 of the upper rail 104protrudes from a region opening between the right and left inner platesections 114 of the lower rail 102. In addition, the sliding space 106is compartmentalized and includes a central space 106 a defined betweenthe left and right inner plates 114, as well as a pair of left and rightside spaces 106 b,106 c on either side of the central space 106 a thatare each defined between the outer plates 110 and the inner plates 114.

As illustrated in FIG. 1 , a plurality of lock holes 118 are formed inone or both of the right and left inner plate sections 114. The lockholes 118 may be intermittently formed in the X direction and may beutilized to lock the position of the upper rail 104 relative to thelower rail 102.

The upper rail 104 includes a pair of side plates 120. As shown in FIGS.1 and 5B, the pair of side plates 120 includes overlapping portions 122a,122 b which extend in the X direction. The side plates 120 may becurved or segmented to at least partially wrap around the left and rightinner plates 114 of the lower rail 102. In the illustrated example, theside plates 120 each are generally U-shaped when evaluated incross-section and include a downwardly extending sidewall portion 124and an upwardly extending sidewall portion 126 joined together by abottom portion 128. The downwardly and upwardly extending sidewallportions 124,126 are spaced apart from each other in the Y dimension andthe plate 114 may extend downward there-between. When assembled, theportions 124 of the side plates 120 may be positioned between the innerplates 114 of the lower rail 102 and within the central compartment 106a of the sliding space 106, and each of the sidewall portions 126 of theside plates 120 may be positioned within the left and right side spaces106 b,106 c. In the illustrated example, a pair of spacers 502 a,502 bare utilized to laterally support the side plates 120 at the desiredwidth.

Rollers 130 are provided on and supported by the upper rail 104. In theillustrated example, the rollers 130 are rotatably mounted to theupwardly extending sidewall portions 126. The rollers 130 roll on a topsurface 132 of the bottom plate 108 of the lower rail 102 and therebyslidingly support the upper rail 104 relative to the lower rail 102. Asdescribed below, in some examples, the rollers 130 may be coupled toupper rail 104 via a slider member positioned on an inner surface 129 ofthe bottom portion 128 of the upper rail 104.

Referring to FIG. 3 , the upper rail 104 may have at least one inclinedsurface 304. As illustrated, provided at opposite ends 302 a,302 b ofthe upper rail 104 are a pair of inclined surfaces 304 a,304 b. Theinclined surfaces 304 are formed into the sidewall portion 126 of theupper rail 104. As described below, an engagement assembly 306 slidablyabuts on each of the inclined surfaces 304. In particular, a pair ofengagement assemblies 306 a,306 b slidably abut on a respective one ofthe inclined surfaces 304 a,304 b. Each of the engagement assemblies 306a,306 b also abuts on an interior upper surface 134 (see FIG. 2 ) of theupper plate sections 112 of the lower rail 102. In this manner, theupper rail 104 is constrained within the sliding compartment 106 of thelower rail 102, between the bottom plate section 108 and the upper platesections 112, via the rollers 130 and the engagement assemblies 306a,306 b.

FIG. 5B illustrates an example of the upper rail 104 utilizable with theseat rail assembly of FIGS. 1-4 . As shown, the inclined surfaces 304a,304 b extend along the upper rail 104 in the X direction, and are eachinclined or sloped upward in the Z direction as they approach each other(and are inclined or sloped downwards in the Z direction as they extendaway from each other and toward their respective end 302 a,302 b). Forexample, as illustrated in FIG. 3 , the inclined surface 304 a proximatethe left end 302 a has a positive slope, whereas the inclined surface304 b proximate the right end 302 b has a negative slope. Stateddifferently, the slopes of the inclined surfaces 304 a,304 b are ofopposite sign (e.g., the inclined surface 304 a may have a positive (+)value slope and the inclined surface 304 b may have a negative (−) valueslope, and vice versa). The inclined surfaces 304 a,304 b are inclinedor sloped so as to approach lower surfaces 134 of the upper platesections 112 of the lower rail 102. Moreover, regardless of whether theinclined surfaces 304 a,304 b have slopes of the same or differentsigns, the inclined surfaces 304 a,304 b may have slopes of equalmagnitude (i.e., equal absolute value but opposite in sign, or they haveslopes which are negative of each other). However, the inclined surfaces304 a,305 b may have slopes of different magnitude. In addition, theinclined surfaces 304 a,304 b may have the same or different travellengths. For example, the inclined surfaces 304 a,304 b may slope in thesame direction (i.e., they may both be positive (+) or negative (−)value slope), and may extend in such same direction toward either thefirst end or the second end 302 a,302 b of the upper rail 104.

FIGS. 6A and 6B illustrate an example engagement assembly 306 featuringa dual wedge design, according to one or more embodiments of the presentdisclosure. In particular, FIG. 6A illustrates the left hand sideengagement assembly 306 a of FIG. 3 , whereas FIG. 6B illustrates theright hand side engagement assembly 306 b of FIG. 3 . While beingpositioned at opposite ends 302 a,302 b of the upper rail 104, the pairof the engagement assemblies 306 a,306 b may be identical with eachother. The engagement assemblies 306 a,306 b are positionable on theupper rail 104 within the left and right side spaces 106 b,106 c of thesliding space 106 defined by the lower rail 102. The engagementassemblies 306 a,306 b are slidable on the inclined surfaces 304 a,304 bof the upper rail 104.

The engagement assemblies 306 a,306 b each includes a lower engagementmember 602 and an upper engagement member 604. The lower and upperengagement members 602,604 are each configured as a wedge shaped member,such that the engagement assembly 306 incorporates a dual wedge design.The lower engagement member 602 includes a lower inclined surface 606that abuts and is slidable on the inclined surfaces 304 a,304 b of theupper rail 104. Thus, the lower engagement member 602 is slidable on theupper rail 104. In addition, the lower engagement member 602 includes anupper inclined surface 608. The upper engagement member 604 includes alower contact surface (obscured from view) that abuts on and is slidableon the upper inclined surface 608 of the lower engagement member 602.Thus, the upper engagement member 604 is slidable and movable on theupper inclined surface 608 of the lower engagement member 602. Also, theupper engagement member 604 includes an upper surface 610 that abuts andis slidable on the lower surfaces 134 of the upper plate sections 112 ofthe lower rail 102. In the illustrated example, an inclined or slopedchannel or track 612 is defined in the lower engagement member 602 andthe upper engagement member 604 has a pair of retaining legs 614 a,614 bthat slide within the track 612, thereby slidably retaining the lowercontact surface of the upper engagement member 604 to maintain contactwith the upper inclined surface 608 of the lower engagement member 602.The lower engagement member 602 also includes a stop feature 616 formedso as to contact the retaining legs 614 a of the upper engagement member604 and thereby inhibit further travel of the upper engagement member604 in the track 612.

Each of the engagement assemblies 306 a,306 b also includes an extensionspring 620 and a torsion spring 622. The extension spring 620 has afirst end 624 connected to the upper rail 104 and a second end 626connected to the lower engagement member 602. The extension spring 620applies a bias on the lower engagement member 602 as described below. Inother examples, another type of biasing element is utilized instead ofthe extension spring 620, such as a torsion spring or compressionspring. The extension spring 620 applies a biasing force on the lowerengagement member 602 that is independent of the travel direction ofeither the lower or upper rails 102,104. In other non-illustratedexamples, the extension springs 620 are oppositely provided such thatthe biasing force that they apply is flipped 180 degrees from thatillustrated.

The torsion spring 622 is sprung to bias the upper engagement member 604towards the stop feature 616. In other examples, the stop feature 616may be provided at an opposite end of the track 612 in addition to orinstead of as illustrated. In particular, the torsion spring 622 is setwithin an embossment 621 formed on the lower engagement member 602, andapplies force on a back side 623 of the upper engagement member 604.Thus, the torsion spring 622 biases the upper engagement member 604 intoa default position, as illustrated in FIGS. 6A and 6B, where the upperengagement member 604 abuts against the stop feature 616 of the lowerengagement member 602. When acted upon by the lower rail 102 asdescribed below, the upper engagement member 604 may travel relative tothe lower engagement member 602 along the channel or track 612 in adirection opposite the stop feature 616 against the biasing forceapplied by the torsion spring 622. As illustrated in FIG. 7A, the upperengagement member 604 may continue traveling in that opposite direction702 until it reaches an extreme position 704 where further travel isinhibited by the torsion spring 622. Thus, the torsion spring 622 alsofunctions to inhibit travel of the upper engagement member 604 on thelower engagement member 602 beyond the extreme position as describedbelow. Similarly, the torsion spring 622 applies a biasing force on theupper engagement member 604 that is independent of the travel directionof either the lower or upper rails 102,104. In the illustrated example,the lower engagement member 602 and the upper engagement member 604 arebiased in opposite directions, and, also in the illustrated example, thelower engagement member 602 and the upper engagement member 604 arebiased towards a maximum thickness of the engagement assembly 306. Inother non-illustrated examples, both the lower and upper engagementmembers 602,604 are biased by extension springs, or both biased bycompression springs, or both biased by torsion springs, or both biasedby different types of springs, etc.

The relative sliding between the lower engagement member 602 and theupper engagement member 604 changes the distance between the lowersurface 606 of the lower engagement member 602 and the upper surface 610of the upper engagement member 604 (i.e., the stack height) such thateach of the engagement assemblies 306 a,306 b may maintain constantsupport and contact between inclined surfaces 304 a,304 b of the upperrail 104 and the lower surfaces 134 of the upper plate sections 112 ofthe lower rail 102 despite vehicle movement, or undulation or variationresulting from manufacture, as mentioned above. For example, in FIG. 7A,the stack height of the lower and upper engagement members 602, 604(i.e., the distance between the lower surface 606 of the lowerengagement member 602 and the upper surface 610 of the upper engagementmember 604) is the smallest when the upper engagement member 604 is inthe extreme position 704, and is the largest when in the defaultposition shown in FIGS. 6A and 6B.

Thus, the engagement assembly 306 maintains contact between the lowerrail 102 and the upper rail 104. In particular, the lower engagementmember 602 maintains contact with the upper rail 104 and the upperengagement member 604 maintains contact with the lower rail 102.However, in some examples, one or more of the engagement assemblies 306may be flipped upside-down such that the upper engagement member 604maintains contact with the upper rail 104 and the lower engagementmember 602 maintains contact with the lower rail 102. In the illustratedexample, the engagement assembly 306 contacts an interior surface of thelower rail 102, but in other examples, the engagement assembly 306 maycontact an exterior surface of the lower rail 102. Similarly, in theillustrated example, the engagement assembly 306 contacts an interiorsurface of the upper rail 104, but in other examples, the engagementassembly 306 may contact an exterior surface of the upper rail 104. Asmentioned, the lower engagement member 602 maintains contact with asurface of the upper rail 104 and the upper engagement member 604maintains contact with a surface of the lower rail 102. The surface ofthe lower rail 102 and/or the surface of the upper rail 104 contacted bythe engagement assembly 306 may be an inclined surface. The portion ofthe engagement assembly 306 which slides on the inclined surface may bea side surface of the engagement assembly 306. For example, a sidesurface of the upper engagement member 604 may slide on the inclinedsurface of the upper rail 104, and a side surface of the lowerengagement member 602 may slide on an interior surface of the lower rail102. Thus, the engagement assembly 306 may be utilized to eliminatelateral rattling as well as (or instead of) vertical rattling of thelower and upper rails 102,104.

While FIG. 7A illustrates a travel or slide path of the upper engagementmember 604 on the lower engagement member 602, FIG. 7B illustrates atravel or slide path of the lower engagement member 602 relative to theupper rail 104. In particular, FIG. 7B illustrates the lower engagementmember 602 situated on the inclined surface 304 of the upper rail 104 ina default or nominal position 710, but movable forward or backwardtherefrom into a first extreme position 712 or a second extreme position714. The lower engagement member 602 carries the upper engagement member604, and those two members together are movable or slidable relative tothe upper rail 104 between a first extreme position and a second extremeposition. The extension spring 620 biases the lower engagement member602 towards the second extreme position 714, and, when the upper rail104 travels in a direction 716 relative to the lower rail 102, frictioncauses the lower engagement member 602 to move downward along the slopedincline surface 304 in a sliding direction 718 (with the upperengagement member 604 carried thereon and inhibited from moving relativeto the lower engagement member 602 due to the stop feature 616) withminimal effect on sliding effort/resistance.

The inclination or slope of the inclined surfaces 304 a,304 b of theupper rail 104 helps accommodate any variation in the gap between thelower and upper rails 102,104 which may result during manufacture orvehicle movement. As shown in FIG. 7B, when the upper engagement member604 is fully biased against the stop feature 616 (in the slidingdirection 718) on the lower engagement member 602, the upper engagementmember's 604 upper surface 610 is relatively higher when the lowerengagement member 602 is in the second position 714 than it is when thelower engagement member 602 is in the other extreme position 712 due tothe inclination of the inclined surfaces 304 a,304 b of the upper rail104.

Referring back to FIG. 7A, which illustrates the sliding or travel pathof the upper engagement member 604 relative to the lower engagementmember 602, the upper engagement member 604 is configured to slidewithin the track 612 formed in the lower engagement member 602 and isconstrained between a first extreme position (where the upper engagementmember 604 abuts the stop feature 616) and a second extreme position(where the upper engagement member 604 fully travels in direction 702until the torsion spring 622 restricts any further travel). In anotherexample, the stop feature 616 may be located on the opposite end of thetrack 612. By locating the stop feature 612 on one end of the track 612,the upper engagement member 604 may be slid onto the lower engagementmember 602 during assembly. In even other examples, stop features 616may be located on both ends of the track 612 and, during assembly, theupper engagement member 604 may be snapped onto the track 612 of thelower engagement member 602.

When not acted upon by sufficient frictional forces from movement of thelower rail 102 or the upper rail 104 (i.e., when installed in a vehicle,for example, with a seat and/or when a user thereon), the engagementassembly 306 is designed to locate in the default or nominal position710 as shown in FIG. 7B. When in the default or nominal position 710,the lower engagement member 602 is substantially centered along thelength of the inclined surface 304 of the upper rail 104 and the upperengagement member 604 is biased into the extreme position where it ispressed against the stop feature 616 in the direction of the springforce applied by the torsion spring 622 (see FIG. 7A). When the lowerengagement member 602 is centered along the inclined surface 304, in thedefault or nominal position 710, the engagement assembly 306 has enoughrange of travel along the upper rail's inclined surface 304, in eitherthe direction 716 or an opposite direction 720, to accommodate theexpected vertical stack variation between the lower and upper rail102,104 which may be encountered (due to manufacturing tolerances) asthe upper rail 104 moves relative to the lower rail 102. Also, the upperengagement member 604 has enough travel range along the lower engagementmember's 602 sloped track 612 to accommodate any vertical stackvariation between the upper rail 104 and the lower rail 102 that may beencountered, when the upper rail 104 moves in the opposite direction 720relative to the lower rail 102. This relative movement of the upperengagement member 604 and the lower engagement member 602 ensuresconstant contact between the lower rail 102 and the upper rail 104 whilesimultaneously preventing any instances of binding between the rails102,104. For example, when the automobile seat and the upper rail 104move in the direction 716, the lower engagement member 602 displaces inthe downward direction 718 along the upper rail's 104 inclined surface304 with minimal effect on sliding effort or resistance. In contrast,when the automobile seat and the upper rail 104 move in the oppositedirection 720, the upper engagement member 604 may displace in adownward direction 702 along the lower engagement member's 602 track 612with minimal effect on sliding effort or resistance. This relativemovement of the upper engagement member 604 and the lower engagementmember 602 prevents binding while maintaining constant contact betweenthe upper rail 104 and the lower rail 102.

For example, the upper engagement member 604 may displace in a downwarddirection 702 if the gap between lower rail 102 and the upper rail 104is reduced while the upper rail 104 moves in the opposite direction 720.Alternatively, if the gap remains constant or becomes larger while theupper rail 104 moves in the direction 720, binding should not occur andthe upper engagement member 604 will not move. If the gap becomes largerwhile the upper rail 104 moves in the opposite direction 720, the spring620 should bias the lower engagement member 602 toward the nominalposition along the inclined surface 304 to maintain constant contactbetween the upper rail 104 and the lower rail 102.

FIGS. 8A and 8B illustrate other aspects of how the engagementassemblies 306 may interact with the upper rail 104. As illustrated inFIG. 8A, the upper rail 104 may include slots 802 a,802 b for receivinga portion of the lower engagement member 602 described below. The slots802 a,802 b are positioned beneath the inclined surfaces 304 a,304 b,respectively, and the slots 802 a,802 b may be sloped or inclined in anorientation matching that of their respective inclined surfaces 304a,304 b. Thus, the first slot 802 a may have the same slope orinclination as the inclined surface 304 a, and the other slot 802 b mayhave the same slope or inclination as the other inclined surface 304 b.For example, the slots 802 and their corresponding inclined surfaces 304may be parallel with each other (i.e., the slot 802 a is parallel withthe inclined surface 304 a and the slot 802 b is parallel with theinclined surface 304 b). In this manner, the lower engagement member 692(and the engagement assembly 306) moves linearly along linear pathsdefined by the slots 802 and their corresponding inclined surfaces 304.Thus, in examples where the orientation of either or both of theinclined surfaces 304 a,304 b is changed (i.e., flipped), theorientation of the slots 802 a,802 b may be correspondingly changed.Also, the lower engagement member 602 of the engagement assemblies 306a,306 b may have a pair of legs 810,812 spaced apart from each other todefine a channel 814. When assembled, the lower engagement member 306rides on the inclined surface 304, with the spaced apart legs 810,812straddling the sidewall 126 of the upper rail 104, such that a portion816 of the sidewall 126 proximate to the inclined surfaces 304 isinserted within the channel 814 of the lower engagement member 602.Thus, the spaced apart legs 810,812 and the corresponding channel 814formed thereby are dimensioned according to a thickness of the portion816 of the upper rail's 104 sidewall 126. Also, a guide pin 818 isprovided on the lower engagement member 602 and arranged to be receivedwithin the corresponding guide slot 802 a or 802 b. Here, the guide pin818 is provided on the second leg 812 and protrudes therefrom into thechannel 814; however, the pin 818 may instead be provided on the otherleg 810, or a pin may be provided on both legs 810,812. When assembled,the lower engagement member 306 rides on the inclined surface 304, withthe portion 816 of the sidewall 126 proximate to the inclined surfaces304 inserted within the channel 814 of the lower engagement member 602and with the pin 818 riding within the guide slot 802 to help retain theengagement assembly 306 on the upper rail 104.

FIGS. 9A and 9B illustrate a relative movement of the lower and upperengagement members 602,604, according to one or more examples of thepresent disclosure. As illustrated in FIG. 9A, the lower engagementmember 602 travels along the inclined surface 304 of the upper rail 104along a primary path 902, and the upper engagement member 604 travelsalong upper surface 608 of the lower engagement member 602 (and withinthe channel or track 612 thereof) along a secondary path 904. Theinclined surface 304 may be oriented at various angles θ relative tohorizontal, such that the corresponding path 902 may similarly beoriented at various angles θ relative to horizontal. In the illustratedexample, inclined surface 304 and the corresponding primary path 902 areoriented at an angle θ of 6 degrees. Also, the upper surface 608 (andthe channel or track 612) of the lower engagement member 602 may beoriented at various angles θ′ relative to horizontal, such that thecorresponding secondary path 904 may similarly be oriented at variousangles θ′ relative to horizontal. In the illustrated example, inclinedsurface 304 and the corresponding path 902 are oriented at an angle θ′of 6 degrees. The angles θ, θ′ may vary depending the amount of freeplay or looseness between the rails 102,104 and based on the travelamounts of the rails 102,104.

FIG. 9B illustrates the degree of movement of the lower and upperengagement members 602,604 of FIG. 9A, according to one or more examplesof the present disclosure. The extension spring 620 applies force on thelower engagement member 602 thereby pulling the lower engagement member602 (and the engagement assembly 306) as indicated by arrow 906. Thesystem may be designed to provide the lower engagement member 602various amounts of travel X′ in direction 906. Here, for example, thelower engagement member 602 is configured to allow for up to 8 mm oftravel X′ in direction 906 from the default or nominal position. In theillustrated example, movement of the lower engagement member 602 isconstrained or limited between wall portions 910,912 of the upper rail104. For example, the slots 802 (see FIG. 8A) may be designed withsuitable dimensions to allow for the desired amount of travel X′ indirection 906 from the default or nominal position. Also, the torsionspring 622 applies force on the upper engagement member 604 to therebyurge the upper engagement member 604 in an opposite direction asindicated by arrow 908, and when in use, the upper engagement member maytravel a distance X″ in a direction that is opposite the arrow 908.Here, for example, the upper engagement member 604 is configured toallow for up to 8 mm of travel X″ in the opposite direction from arrow908.

FIGS. 10A and 10B illustrate an alternate example interaction of theengagement assemblies 306 on the upper rail 104. In this example, thelower engagement member 602 includes a single wall 810 and no guide pin.

FIGS. 11A-11B illustrate example lateral control features 1102 to reducerattling between the various components and thereby reduce noise. Thelateral control features 1102 may be provided in an interior surface ofthe U-shaped side plates 120 of the upper rail 104. As shown, thelateral control features 1102 may be mounted on an interior surface 1104of a recess 1106 defined between wall portions 1124,1126,1128.

FIG. 11B illustrates a lateral control feature 1102 according to one ormore examples. In the illustrated example, each of the lateral controlfeatures 1102 is a U-shaped member which includes an inner wall portion1124, an outer wall portion 1126, and a bottom curved wall portion 1128joining the inner and outer wall portions 1124,1126. The wall portions1124,1126,1128 define a channel 1130 into which the left and right innerplates 114 of the lower rail 102 will extend when assembled. Whenassembled, the inner wall portion 1124 will abut the downwardlyextending sidewall portion 124 of the upper rail 104, the outer wallportion 1126 will abut the upwardly extending sidewall portion 126 ofthe upper rail 104, and the curved bottom wall portion 1128 will abutthe bottom portion 128 of the upper rail 104. The lateral controlfeature 1102 includes a pair of outer locking tabs 1132 and an innerlocking tab 1134 that engage edges of a recess formed in the upper railas described below. One or more crush ribs 1136 may be provided withinthe channel 1130 to ensure constant contact and inhibit rattling. Thecrush ribs 1136 are provided on an interior surface of the wall 1124and, when fully assembled, will contact the left and right inner plates114 of the lower rail 102 (see FIG. 2 ). The ribs 1136 may have variousconfigurations and/or dimensions, for example, the ribs 1136 may berounded and elongated as illustrated. In other examples, a leaf springis utilized instead of the ribs. In other examples, both ribs and leafsprings are utilized (on the same side or on opposing sides). Thelateral control feature 1102, including the crush ribs 1136 may be madefrom a non-metallic material, such as plastic, to avoid metal on metalcontact. By contacting the left and right inner plates 114 of the lowerrail 102, the lateral control feature 1102, which is mounted in theupper rail 104 will ensure constant contact between the lower and upperrails 102,104, while avoiding metal on metal contact. In addition, holes1140 are formed in the lateral control feature 1102 to provide clearanceand accommodate the rollers 130 and also to provide a drain for debristhrough the system.

FIG. 12 illustrates an example installation of the lateral controlfeatures 1102 in an end of the upper rail 104. In the illustratedexample, cut-outs 1202 have been formed at an end of the upper rail 104to accommodate the lateral control features 1102. As mentioned, thelocking tabs 1132,1134 of the lateral control features 1102 allow it tosnap into place, as the outer locking tabs 1132 and the inner lockingtab 1134 engage edges of the cut-outs 1202 to thereby lock the lateralcontrol features 1102 within the channel 1130. Also, the cut-outs 1202provide clearance to accommodate the rollers 130 and provide a drain fordebris through the holes 1140 in the lateral control feature 1102 andout of the system.

FIG. 13 illustrates an alternate engagement assembly 1300, according toone or more alternate embodiments. In the illustrated example, thealternate engagement assembly 1300 includes a single engagement member1302 (or single “wedge”). Thus, the engagement assembly 1300 may bereferred to as a single wedge design, as opposed to the above describedengagement assembly 306 which utilizes a pair of engagement members602,604 (i.e., a pair of “wedges”) and which may be referred to as adual wedge design. Here, the engagement member 1302 includes a lowersurface 1304 that, when assembled, abuts and slides on the inclinedsurface 304 of the upper rail 104. Also, the engagement member 1302includes an upper surface 1306 that, when assembled, abuts and slides onthe lower surfaces 134 (not illustrated in FIG. 13 ) of the upper platesections 112 of the lower rail 102.

FIGS. 14A and 14B illustrates an alternate engagement assembly 1400,according to one or more alternate embodiments. In contrast to the abovedescribed engagement assembly 306, which utilizes a pair of springloaded engagement members 602,604 (i.e., a pair of spring loaded“wedges”), the engagement assembly 1400 utilizes a spring loadedrotating feature (or cam) as described below. FIG. 14A is an explodedview of the alternate engagement assembly 1400. FIG. 14B is frontcross-sectional view of the alternate engagement assembly 1400 whenassembled on the upper rail 104 but without the slider feature describedbelow.

As illustrated, the engagement assembly 1400 includes a hub member 1402,a cam member 1404, and a slider member 1406. The hub member 1402 ismounted on the upper rail 104. In the illustrated example, the hub 1402is mounted on a tab 1410 of the upper rail 104, and the hub 1402includes an interior bore 1408 that is keyed to fit on the tab 1410 toinhibit rotation of the hub 1402 about the tab 1410. The hub 1402includes an exterior circular slide surface 1412 on which the cam 1404is configured to rotate. The cam 1404 includes a bore 1414 and ismounted on the hub 1402 such that the bore 1414 of the cam 1404 slideson the slide surface 1412 of the hub 1402. The cam 1404 also includes acam surface 1416 on which the slider member 1406 is provided. The slidermember 1406 includes a lower surface (obscured from view) that engagesthe cam surface 1416 and the slider member 1406 also includes an uppersurface 1418 that will engage the lower surfaces 134 (not illustrated inFIG. 13 ) of the upper plate sections 112 of the lower rail 102. Whilenot illustrated, a biasing member (e.g., a torsion spring) may besupported on the hub 1402 and have a free end that is entrapped orretained by a feature (e.g., an embossment) on the cam 1404, such thatthe cam 1404 is biased into a default position, and urged back into thatdefault position by the biasing member if the cam 1404 has been rotatedclockwise or counter-clockwise out of the default position.Alternatively, a coil spring may be utilized to bias the cam 1404, inwhich a first end of the coil spring is connected to the upper rail 104and a second end of the coil spring is connected to the cam 1404 asdescribed in other examples, above. For example, a torsion spring or anextension spring may be utilized to bias the cam 1404 such that it is aspring-loaded cam. In the illustrated example, the slider member 1406 isnot spring-loaded, but in other examples, it may be spring loaded with atorsion spring or an extension spring. In some examples, a feature 1420is provide to help retain the hub 1402 on the tab 1410 of the upper rail104, for example, a deformable feature for retaining the bore 1406 ofthe hub 1402 on the top radius of the tab 1410. The feature 1420 may bea snap-fit feature (or finger) integral with the hub 1402 that snapsinto place upon insertion of the hub 1402 onto the tab 1410 and therebysecure the hub 1402 onto the upper rail's 104 tab 1410.

The slider member 1406 may have various lower surface configurations.FIGS. 15A-15D illustrate alternate lower surface configurations for theslider member 1406, according to various aspects of the presentdisclosure. In particular, FIG. 15A illustrates the slider 1406 of FIG.14 , wherein the slider 1406 includes a circular slider surface 1502configured for full contact with the cam surface 1416 of the cam 1404,as indicated by arrows 1504. As seen in FIG. 15A, this design improvesthe interface/engagement between the cam 1404 and the slider 1406. Asthe upper rail 104 translates relative to the lower rail 102, the slider1406 remains in full contact with the cam 1402, even during rotation ofthe cam 1402 as indicated by arrow 1506, due to the matching curvaturesof the slider surface 1502 and the cam surface 1416. In some examples,the slider 1406 may include a retaining leg feature that hooks around aportion of the cam 1404, such that the slider 1406 is slidably retainedon the cam 1404. Also, cam lock angles may vary, for example, from about8 degrees through the range of tolerance.

FIG. 15B illustrates the slider 1406 of FIG. 14 , wherein the slider1406 includes a flat angled slider surface 1508 configured to contactwith the cam surface 1416 of the cam 1404 at a single point 1510. Thesingle point 1510 is normal to the angled flat slider surface 1508. Theflat angled slider surface 1508 may improve interface to the lowersurfaces 134 (of the lower rail 102), because the single point ofcontact 1510 adds a degree of freedom in both travel directions, and thegeometry of the cam 1404 and its surface 1416 can be modified tomaintain a constant lock angle. Operation of the slider 1406incorporating the flat angled slider surface 1508 is described belowwith reference to FIG. 18 .

FIG. 15C illustrates the slider 1406 of FIG. 14 , wherein the slider1406 includes a flat slider surface 1512 (i.e., without an angle), whichis also configured to contact with the cam surface 1416 of the cam 1404at a single point 1514 that is normal to the flat slider surface 1512.The flat slider surface 1512 may improve interface to the lower surfaces134 (of the lower rail 102), because the single point of contact 1512adds a degree of freedom in both travel directions, and the geometry ofthe cam 1404 and its surface 1416 can be modified to maintain a constantlock angle.

FIG. 15D illustrates the slider 1406 of FIG. 14 , wherein the slider1406 includes a semi or partial circular slider surface 1516. Ascompared to the circular slider surface 1502 of FIG. 15A, the semi orpartial circular slider surface 1516 of FIG. 15D is shorter andtherefore has less points of contact 1518. It should be appreciated,however, that the semi or partial circular slider surface 1516 of FIG.15D may have a larger or even smaller length than as illustrated. Thesemi or partial circular slider surface 1516 of FIG. 15D also improvesthe interface to the lower surfaces 134 (of the lower rail 102).

FIGS. 16A-16C illustrates an alternate engagement assembly 1600utilizing the cam 1406, according to one or more alternate embodiments.In this example, a single cam 1406 is utilized. As illustrated, the cam1406 may rotate, as indicated by arrow 1602, to take up (or account for)height variation 1604 that may be prevalent in the lower rail 102 andresult from manufacturing long lower rails 102 as discussed above.

FIGS. 16B and 16C illustrate example operation of the engagementassembly 1600. In FIG. 16B, the lower rail 102 and the upper rail 104are moving relative to each other, with the lower rail 102 moving indirection 1612 and the upper rail moving in direction 1614, and with thecam 1404 subject to a cam spring force 1616. Here, the motion 1612 ofthe lower rail 102 is oppositely directed from the spring force 1616,resulting in an applied force 1620 being applied to the cam surface 1416as illustrated, wherein the applied force 1620 includes both the normalforce plus any frictional forces. The frictional forces may beconsistent based on spring output.

In FIG. 16C, the lower rail 102 and the upper rail 104 are movingrelative to each other in opposite directions as shown in FIG. 16B, withthe lower rail 102 moving in direction 1632 and the upper rail moving indirection 1634, and with the cam 1404 subject to the same cam springforce 1616. Here, the motion 1632 of the lower rail 102 is in the samedirection as the application of the spring force 1616, resulting in anapplied force 1640 being applied to the cam surface 1416 as illustrated.

FIG. 17 illustrates an alternate cam engagement assembly 1700, accordingto one or more alternate embodiments. In the illustrated example, theengagement assembly 1700 is a dual cam engagement assembly having afirst cam 1702 and a second cam 1704. The first and second cams 1702,1704 overlap each other. The first cam 1702 is slidably positioned onthe hub surface 1412 of the hub 1402. The second cam 1704 is slidablypositioned on an outer cam surface 1706 of the first cam 1702. Thesecond cam 1704 includes an outer cam surface 1708 which contacts orabuts the inner surface of the lower rail 102. Thus, the first cam 1702may be referred to as the inner cam, and the second cam 1704 may bereferred to as the outer cam. The first cam 1702 is subject to a camspring force 1710. Here, the lower rail 102 and the upper rail 104 aremoving relative to each other, with the lower rail 102 moving indirection 1712 and the upper rail 104 moving in direction 1714. Thismotion results in applied forces 1720 being applied to the cams' surfaceas illustrated, wherein the applied force 1720 includes both the normalforce plus any frictional forces.

FIG. 18 illustrates an example operation of the engagement assembly ofFIG. 15B. In this example, the slider 1406 includes the flat angledslider surface 1508 configured to contact with the cam surface 1416 ofthe cam 1404 at a single point 1510. Here, the lower rail 102 and theupper rail 104 are moving relative to each other, with the lower rail102 moving in a direction 1802 and the upper rail 104 moving in anopposite direction 1804, resulting in applied forces 1820 being appliedat the interaction of the flat angled slider surface 1508 and the camsurface 1416 and between the inner surface of the lower rail 102 and theupper surface of the slider 1406.

FIG. 19 illustrates an alternate engagement assembly 1900, according toone or more alternate embodiments. In the illustrated example, theengagement assembly 1900 is a dual wedge engagement assembly having afirst wedge 1902 and a second wedge 1904. The first wedge 1902 is biasedin a first direction 1906 via a first biasing member 1908, and thesecond wedge 1904 is biased in a second direction 1910 via a secondbiasing member 1912. Here, the first and second biasing members1910,1912 are extension springs; however, other types of biasing membersmay be utilized without departing from the present disclosure, asdescribed herein. In the illustrated example, the first wedge 1902includes a lower surface 1914 that is slidable on a surface 1916 of theupper rail 104, and the second wedge 1904 includes an upper surface 1918that is slidable on a surface 1920 of the lower rail 102, as describedherein. Also, the first wedge 1902 includes an upper inclined surface1922 and the second wedge 1904 includes a lower inclined surface 1924that abuts and slides on the upper inclined surface 1922 of the firstwedge 1902 as described herein.

Embodiments herein pertain to seat rail assemblies 100 utilizingrelatively long rails (or tracks) 102 which engage repeating slots 118to drive and hold load. Even when manufactured with tight tolerances,there will likely still be backlash (e.g., lash, play, or slop) in thesystem exceeding customer requirements. Gearboxes with drive screws areutilized to drive the upper rail 104 within the lower rail 102, and thislongitudinal slop may be inhibited by modifying the internal assembly ofthe gearbox and how the gearbox's screws engage the longitudinal slots118 in the lower rail 102. Accordingly, gearboxes may be provided withone or more active lobe features for removing longitudinal play betweenthe (gear box's) drive screw threads and the lower rail slots 118. Asdescribed herein, the active lobe may be positioned outside of thegearbox's bearing plates such that longitudinal play between the drivescrew threads and the slots 118 is removed and longitudinal play isremoved from within the gearbox that would otherwise exist between thebearing end plates.

FIG. 20 illustrates a gearbox 2000 utilizable to drive the railassemblies described herein, according to one or more embodiments of thepresent disclosure. In the illustrated example, the gearbox 2000 isattached to the upper rail 104 and operable to drive or translate theupper rail 104 relative to the lower rail 102. As hereinafter described,the gearbox 2000 includes a drive screw and is configured to manage oreliminate backlash caused by gaps or clearance between the drive screwand the lower rail slots 118.

Here, the gearbox 2000 includes at least one drive screw 2002, a lobe2004 associated with each of the at least one drive screws 2002, and ahousing 2006 within which the drive screw 2002 and associated lobe 2004are provided. As hereinafter described, the lobe 2004 is spring-loaded(in other words, an “active lobe”) such that it may operate to removeclearance that may otherwise exist between the drive screw 2002 and theslots 118 in the lower rail 102. The housing 2006 may include one ormore legs 2008 configured to be inserted into corresponding slots (notshown) in the upper rail 104 (not shown). The gearbox 2000 includes aninput 2010 into which an external drive shaft (not illustrated) or otherexternal source of power may be inserted. The input 2010 is rotationallyfixed to a drive gear 2012, such that the input 2010 and the drive gear2012 rotate together (in unison). The drive screw 2002 includes a shaft(obscured from view) about which a thread 2014 extends. A driven gear2016 is mounted on the shaft of the drive screw 2002 such that its teethmesh with teeth on the drive gear 2012, and the driven gear 2016 isrotationally fixed to the drive screw shaft, such that the drive screwshaft and the driven gear 2016 rotate together (in unison). Accordingly,rotation of the input 2010 (e.g., via an exterior drive shaft) causesrotation of the drive gear 2012, which in turn drives the driven gear2016 due to the intermeshing of the teeth of the driven gear 2016 withthe teeth of the drive gear 2012, thereby causing rotation of the drivescrew shaft and the thread 2014 of the drive screw 2002. Furthermore,the lobe 2004 includes a thread 2020 that abuts or contacts the thread2014 of the drive screw 2002, such that rotation of the drive screw 2002thereby causes rotation of the lobe 2004.

The housing 2006 may comprise a plurality of housing portions. In theillustrated example, the housing 2006 includes at least a first (e.g.,lower or base) section 2022 and a second (e.g., upper or lid) section2024. The housing 2006 retains a pair of bearing plates 2030 a,2030 b,and the bearing plates 2030 a,2030 b rotatably support the shafts of thedrive screws 2002 as hereinafter described. In the illustrated example,the bearing plate 2030 a is positioned between the lobe 2004 and thedrive screw 2002; however, as described below, in some examples, thelobe 2004 may be positioned between the bearing plate 2030 a and thedrive screw 2002.

When the gearbox 2000 is assembled on the upper rail 104, the threads2014 engage the lock holes 118 formed on the right and left inner platesections 114 of the lower rail 102, such that actuation (rotation) ofthe drive screw 2002 translates the upper rail 104 relative to the lowerrail 102.

FIG. 21 illustrates an exploded view of another example gearbox 2100where the upper section 2024 of the housing has been removed. Also, FIG.21 illustrates an example of the gearbox 2100 comprising a pair of thedrive screws 2002 a,2002 b and a pair of corresponding lobes 2004 a,2004b. The base section 2022 of the housing 2006 has a pair of wells 2102a,2012 b shaped and sized to receive the drive screws 2002 a,2002 b andthe corresponding lobes 2004 a,2004 b.

The drive screws 2002 a,2002 b each have a shaft 2104 on which theirthread 2014 helically extends about. The driven gear 2016 is mounted ata first end (obscured from view) of the shaft 2104, whereas an opposingsecond end 2106 of the shaft 2104 extends beyond the thread 2014 and isprovided without any helically extending thread. The lobes 2004 a,2004 bhave a bore 2108 and are positioned on the second end 2106 of theircorresponding shaft 2104. In this manner, the lobes 2004 a,2004 b canfreely rotate on their corresponding shaft 2104 relative to theirassociated drive screw 2002 a,2002 b. In the illustrated examples, thelobes 2004 a,2004 b can freely rotate on their shaft 2104 for a limitedrange of rotation relative to their associated drive screw 2002 a,2002b.

The lobes 2004 a,2004 b are each spring loaded. In the illustratedexample, a lobe spring 2110 is provided in the bore 2108 of each lobe2004 a,2004 b, such that the shaft 2104 extends through both the lobe2004 a,2004 b and the corresponding spring 2110. In the illustratedexample, an embossment feature 2111 is provided on an end of each lobe2004 a,2004 b, where the portion of the bore 2108 that extends throughembossment features 2111 is slightly larger in radius than the remainingbore portion of the lobe such that the lobe spring 2110 may be providedwithin the embossment feature 2111 and receive end 2106 of the shaft2104 without interference. Thus, the bore 2108 may be slightly larger indimension at the embossment feature 2111 so as to accommodate the lobespring 2110, which has substantially the same bore dimension as theremaining portion of the bore through the lobes 2004 a,2004 b. Whenassembled, each of the lobe springs 2110 includes a pair of spring ends2112 a,2112 b configured to engage one of the lobes 2004 a,2004 b andone of the shafts 2104. In particular, when assembled, the first springend 2112 a is retained in a slot or opening 2114 provided on each lobe2004 a,2004 b proximate to the bore 2108, and the second spring end 2112b is retained/engaged within a slot 2116 provided in the second end 2106of each shaft 2104. The lobe spring 2110 applies rotational spring forceto the lobe 2004 a,2004 b such that, as the shaft 2104 rotates, the lobespring 2110 may thereby apply a biasing force to the lobe 2004 a,2004 babout the shaft 2104. In this manner, each of the lobes 2004 a,2004 b isrotationally biased about the shaft 2104. Thus, each of the lobes 2004a,2004 b is coupled to its associated drive screw 2002 a,2004 b via itslobe spring 2110, and, while each of the lobes 2004 a,2004 b may rotateindependent of its associated drive screw 2002 a,2004 b, suchindependent rotation is constrained or limited by the lobe spring 2110which adds rotation force to the lobe 2004 a,2004 b depending onrotation of the drive screw 2002 a,2002 b.

In the illustrated example, the drive screws 2002 a,2002 b also eachinclude a pressure plate 2118 and a washer 2120, and all of thecomponents are held in place with a bearing plate assembly 2122. In theillustrated example, the washers 2120 are wavy washers and, whenassembled, one face of the pressure plate 2118 contacts the embossmentfeature 2111 of the lobe 2004 a,2004 b and an opposite face of thepressure plate 2118 contacts the wavy washer 2120 and thereby absorbsforce of the wavy washer 2120 without contacting lobe spring 2110. Thebearing plate assembly 2122 includes a plate 2124 and a pair ofrotatable couplings 2126 a,2126 b supported by the plate 2124. Each ofthe rotatable couplings 2126 a,2126 b may rotate within the plate 2124and are configured to each receive one of the ends 2106 of the shaft2104, such that the ends 2106 of the shaft 2104 are rotationallysupported by the bearing plate assembly 2122 when assembled. In theexample embodiment of FIG. 21 , the bearing plate 2122 a is provided atthe end 2106 of the shaft 2104, such that the lobes 2004 a,2004 binterpose the bearing plate 2124 and the threads 2014 of the drivescrews 2002 a,2002 b. However, the bearing plate 2122 a may bedifferently positioned, for example, the bearing plate 2122 a may bepositioned to interpose the threads 2014 and corresponding lobes 2004a,2004 b. Also, the bearing plates 2122 a,2122 b are retained withinslots 2128 formed in the housing 2006. Here, the slots 2128 may beprovide in both the lower and upper housing sections 2022,2024 and theslots 2128 are formed so as to position bearing plate 2122 a at theterminal ends of the shafts 2104 proximate the lobes 2004 a,2004 b (andopposite the threads 2014 of the drive screws 2002 a,2002 b).

FIG. 22 illustrates example operation of a drive train of the gearbox2100 of FIG. 21 . In particular, FIG. 22 illustrates how each of thelobes 2004 a,2004 b are spring loaded via the lobe springs 2110, suchthat the lobes 2004 a,2004 b are “active” rather than just beingfree-floating. In the illustrated example, the lobe springs 2110 apply acounter clockwise torsional spring force on the lobes 2004 a,2004 babout their shafts 2104 as indicated by arrows 2200. The spring loadedlobes 2004 a,2004 b fill any clearance in the slots 118 of the lowerrails 102, thereby eliminating any fore/aft slop.

This torsional force 2200 rotates the associated lobe 2204 a,2004 bindependent of the associated drive screw 2002 a,2002 b, which therebyeffectively increases the pitch of a single thread. In other words, thepitch is increased between the active lobe and the last thread on thedrive screw. In particular, each lobe spring 2110 increases the widthbetween the thread 2020 of the lobe 2204 a,2004 b and a final thread2202 of the drive screws 2002 a,2002 b. The increasing width between thefinal screw thread 2202 and the lobe thread 2020 fills any additionalclearance within the slots 118 of the lower rail 102. In one example,the active lobe maintains a pressure angle that removes an opportunityfor back-drive under longitudinal loading. The pressure angle is definedby the contact surface between the active lobe thread and the lower railslot 118. In a particular example, a pressure angle of 7.4 degrees isselected to prevent back-drive under longitudinal loading. Here, thecombination of no back-drive and no clearance between threads and theslots 118 in the lower rail 102 results in no longitudinal free play.

FIG. 23 is an end view of the drive train of FIG. 22 . In particular,FIG. 23 illustrates an example configuration of the lobe spring 2110interacting with the shafts 2104 and the associated lobe 2204 a,2004 b.FIGS. 24A and 24B illustrate example operation of the active (i.e.,spring loaded lobes 2004 a,2004 b) and how they operate to remove slopin the system. In particular, FIG. 24A illustrates a system where thelobes 2004 are not spring-loaded (or active) as described herein, whichresults in a gap (or clearance) 2400 existing on the same side of thethreads of the drive screw 2002 and lobe 2004, between such threads andthe slots 118 of the lower rail 102. This results in back lash (or slopor free play). FIG. 24B illustrates how such free play is eliminated byactivating the lobes 2004, for example, with the lobe springs 2110imparting a torsional spring force 2200 on the lobes 2004 a,2004 b abouttheir shafts 2104, which thereby drives the lobes 2004 in a directionindicated by arrow 2402 (relative to the shaft 2104 of the drive screw2002) and thereby closes the gap between the lobe 2004 and the slot 118,as indicated by arrow 2404. Thus, the lobe 2004 contacts a first side ofone of the slots 118, indicated by the arrow 2404, whereas the divescrew 2002 threads contact an opposite side of the slots, as indicatedby arrow 2406, such that there is no slop or free play. In this manner,the lobes 2004 a,2004 b spring loaded by the springs 2110 (i.e., theactive lobes) eliminate the longitudinal free-play associated with lowerrail's 102 slots 118 and the thread of the drive screw 2002.

The spring-loaded active lobe 2004 rotates as shown by arrow 2200 untila tooth A of the lobe 2004 contacts an opposite tooth wall B of thelower rail 102, thereby eliminating the gap as indicated by 2404. TeethC-G of the drive screw 2002 are the threads 2014 of the drive screw 2002and, because the pitches of the threads 2014 of the drive screw 2002 arefixed and uniform, the drive screw 2002 without an active lobe will havelongitudinal free-play that is equal to the amount of clearance betweenthe thread of the drive screw 2002 and the slots 118 of the lower rail102. However, incorporating the lobe tooth A of the lobe 2004 which isspring loaded by the spring 2110, creates a wedge in cooperation withtooth C of the drive screw 2002, which thereby eliminates free-play orslop.

As previously mentioned, rotation of the active lobe 2004 relative tothe drive screw 2002 is limited. FIG. 25 illustrates an example of thedrive screw 2002 configured to limit rotation of the lobe 2004,according to one or more embodiments. In particular, FIG. 25 illustratesone of the lobes 2004 a, but it should be appreciated that the principledescribed in this figure is applicable to the other lobe 2004 b. Thus,this figure is described with reference to an individual one of thelobes 2004. In the illustrated example, a feature 2502 is provided onthe shaft 2104 proximate to the shaft end 2106. Here, the feature 2502is a flat surface formed into the circumference of the shaft 2104. Thefeature 2502 is configured to allow a limited amount of rotation of thelobe 2004 relative to the shaft 2104. Here, the feature 2502 allows forabout 10 degrees of relative rotation of the lobe 2004, which issufficient to eliminate system clearance. However, in other examples,the feature 2502 may have different dimensions to allow for a differentdegree of relative rotation of the lobe 2004 sufficient to eliminateclearance from the system. As described below, a feature is providedwithin the bore 2108 of the lobe 2004 that will engage the flat feature2502 when rotated a certain amount of degrees either clockwise orcounterclockwise.

FIGS. 26-27 illustrate example operation of drive train within thegearbox 2100 to eliminate slop in the system. FIG. 26A illustratescounter-clockwise rotation of the drive gear 2012, as indicated by thearrow 2602. The counter-clockwise rotation 2602 of the drive gear 2012results in clockwise rotation of the driven gears 2016, as indicated bythe arrows 2604, via interaction of the drive gear 2014 with the drivengears 2016 described above. The clockwise rotation 2604 of the drivengears 2016 in turn results in clockwise rotation 2604 of the drivescrews 2002 a,2002 b as such rotation is transmitted through the driveshaft 2104 on which the drive gears 2016 are fixed. Thus,counter-clockwise (2602) motor input results in the drive screws 2002a,2002 b rotating clockwise (2604), which, in the present example, inturn results in the upper rail 104 traveling in a rearward directionalong the lower rail 102. FIG. 26B illustrates a close up of the activelobes 2004 a,2004 b of FIG. 26A, which are fully engaged or sprung viatheir lobe springs 2110. Here, rotation of the drive screw 2002 a,2002 bis transmitted to the lobes 2004 a,2004 b through the springs 2110, andthe springs 2110 may impart a rotation 2604 on the lobes 2004 a,2004 bto close any gap between the lobe tooth A and the tooth B of the slot118 of the lower rail 102. In particular, the rotating drive screw 2002acts on the spring 2110 at its least amount of applied moment (i.e., themoment decreases the further the active lobe 2004 cinches/binds on thelower rail 102 or as the torsional spring approaches its free orunloaded position). The rotating drive screw 2002 acts on the lobespring 2110 when the spring 2110 is applying a minimum moment to theactive lobe 2004. The spring's 2110 minimum moment occurs when the lobespring is approaching its free position (unloaded position) until theactive lobe has removed all longitudinal clearance by contacting a toothwall of a slot of the lower rail that is opposite of the tooth wall thatis contacted by the drive screw or the rotation limiting feature stopsfurther rotation of the active lobe 2004. Thus, clockwise rotationalmovement 2604 of the drive screw 2002 will open up the gap betweenactive lobe 2004 and slots 118 in the lower rail 102 thereby allowingsystem to move with little drag while the spring 2110 operates to closethe gap by urging the lobe 2004 into contact with the lower rail 102. Inparticular, when the drive screw is rotating clockwise when viewed fromthe end of the drive train that includes the drive gear 2012 as shown inFIG. 26A, this results in the upper rail traveling rearward relative tothe lower rail. In the example illustrated in FIG. 22 , the lobe spring2110 is biased in the counter-clockwise direction when viewed from theend of the drive train that includes the active lobe 2004. When viewedfrom the end of the drive train that includes the drive gear 2012 asshown in FIG. 26A, the same example lobe spring 2110 appears to bebiased in the clockwise direction. In this example, the drive screw 2002is rotating in the same direction that the lobe spring 2110 isrotationally biasing the active lobe 2004. The second spring end 2112 bis retained/engaged within a slot 2116 provided in the second end 2106of each shaft 2104, so as the shaft 2014 traverses rearward, it willattempt to pull the lobe rearward out of contact with the opposite toothwall (shown by 2404 in FIG. 24B) while the lobe spring 2110simultaneously rotates the active lobe 2004 further away from the drivescrew in the forward direction to maintain contact with the oppositetooth wall. Since the drive screw is not driving the active lobe 2004further into the opposite tooth wall, additional friction or drag on thesystem is not created.

FIG. 27A illustrates clockwise rotation of the drive gear 2012, asindicated by the arrow 2702. The clockwise rotation 2702 of the drivegear 2012 results in counter-clockwise rotation of the driven gears2016, as indicated by the arrows 2704, via interaction of the drive gear2014 with the driven gears 2016 as described above. Thecounter-clockwise rotation 2704 of the driven gears 2016 in turn resultsin counter-clockwise rotation 2704 of the drive screws 2002 a,2002 b assuch rotation is transmitted through the drive shaft 2104 on which thedrive gears 2016 are fixed. Thus, clockwise (2702) motor input resultsin the drive screws 2002 a,2002 b rotating counter-clockwise (2704),which, in the present example, in turn results in the upper rail 104traveling in a forward direction along the lower rail 102. FIG. 27Billustrates a close up of the active lobes 2004 a,2004 b of FIG. 27A,which are fully engaged or sprung via their lobe springs 2110. Here,rotation 2704 of the drive screw 2002 a,2002 b is transmitted to thelobes 2004 a,2004 b through the springs 2110, and the springs 2110 mayimpart a rotation 2702 on the lobes 2004 a,2004 b to close any gapbetween the lobe tooth A and the tooth B of the slot 118 of the lowerrail 102. In particular, the rotating drive screw 2002 acts on thespring 2110 at its least amount of applied moment (e.g., the momentdecreases the further the active lobe 2004 cinches/binds on the lowerrail 102). Thus, rotational movement 2704 of the drive screw 2002 willbe in the direction of closing the gap between active lobe 2004 andslots 118 in the lower rail 102, thereby adding frictional drag on thesystem. In other words, the drive screw 2002 may be rotating in theopposite rotational direction that the lobe spring 2110 is rotationallybiasing the active lobe 2004. The second spring end 2112 b may beretained/engaged within a slot 2116 provided in the second end 2106 ofeach shaft 2104, so as the shaft 2014 traverses forward, it will attemptto push the lobe forward into contact with the opposite tooth wall(shown by 2404 in FIG. 24B) while the lobe spring 2110 simultaneouslyrotates the active lobe in the forward direction. Since the drive screw2002 would be driving the active lobe 2004 into the opposite tooth wallas the lobe spring 2110 is simultaneously biasing the active lobe 2004into contact with the opposite tooth wall, additional friction or dragon the system would be created. However, the springs 2110 may beselected with spring constants that inhibit cinching/binding of thesystem when the lobe tooth A is urged into contact with the slot 118wall of the lower rail 102. Also, incorporation of the wavy washers 2120may further inhibit cinching/binding of the system.

FIGS. 28A and 28B illustrate an example of the lobe 2004, according toone or more embodiments of the present disclosure. In the illustratedexample, a rotation limiting feature 2802 is formed in the bore 2108 ofthe lobe 2004. Here, the rotation limiting feature 2802 is a pair ofangled flats 2804,2806. As mentioned above, rotation of the lobe 2004about the shaft 2104 is limited by the flat feature 2502 provided on theshaft 2106 of the drive screw 2002. Upon rotation of the lobe 2004clockwise or counterclockwise, one of the angled flats 2804,2806 willcontact the flat feature 2502 of the shaft 2106, thereby inhibitingfurther rotation in that direction; the lobe 2004 may then rotate in theopposite direction about the shaft 2104 until the other one of theangled flats 2804,2806 contacts the flat feature 2502 and inhibitsfurther rotation in that opposite direction. In this manner, the lobe2004 may rotate relative to the shaft 2104 to a degree depending on theangle of the angled flats 2804,2806. For example, if the angled flats2804,2806 were provided without an angle between them, such that theyextended along a horizontal H, they would define a flat surface thatwould constantly abut the flat feature 2502 of the shaft 2106 andthereby inhibit any rotation of the lobe 2004; however, providing theangled flats 2804,2806 at an angle relative to each other, only one ofthe angled flats 2804,2806 will contact the flat feature 2502 of theshaft 2106 at a given time such that the lobe 2004 may rotate in adirection until the other one of the angled flats 2804,2806 contacts theflat feature 2502 of the shaft 2106. FIG. 28B illustrates the angledflats 2804,2806 being angled at an obtuse angle that permits an amountof relative rotation between the lobe 2004 and the shaft 2104; however,the amount of relative rotation between the lobe 2004 and the shaft 2104may be increased by reducing such angle, for example, orienting theangled flats 2804,2806 at an acute angle. Also in the illustratedexample, each of the angled flats 2804,2806 is oriented at an anglerelative to the horizontal H. The flat 2804 is oriented at an angle Φrelative to the horizontal H, and the 2806 is oriented at an angle Vrelative to the horizontal H. In the illustrated example, the anglesΦ,Φ′ are each 10 degrees, such that the lobe 2004 may rotate 10 degreesabout the shaft 2104 in either a clockwise or counter-clockwisedirection before one of the angled flats 2804,2806 contacts the flatfeature 2502 of the shaft 2104; however, different angle values may beselected to provide for more or less relative rotation as may bedesirable.

FIGS. 28A and 28B also illustrate an example of how the lobe spring (notshown) may be provided within the lobe 2004. In the illustrated example,the embossment 2111 protrudes outward from a surface 2808 of the lobe2004 to define a spring pocket 2810 within which the lobe spring may beset. When assembled, the spring 2110 may rest on the surface 2808 of thelobe 2004, with the first spring end 2112 a extending through theopening 2114 in the embossment 2111.

FIG. 29 illustrates an alternate gearbox 2900 utilizable to drive theseat rail assembly described herein. The gearbox 2900 is configured tomanage or eliminate backlash (i.e., lash, play, or slop) caused by gapsor clearance between the drive screw and the slots in the lower rail.Additionally, the gearbox 2900 is configured to manage or eliminatebacklash caused by gaps or clearance between the drive screw and thebearing plates. FIG. 30 is a side cross-sectional view of the gearbox2900 of FIG. 29 . FIG. 31 illustrates an exploded view of the gearbox2900 of FIG. 29 . The gearbox 2900 is similar to the gearbox 2100described above, except that the bearing plate 2122 a of the alternategearbox 2900 is positioned between the drive screw 2002 and the lobe2004. As shown, the housing is configured to retain the bearing plate2122 a in such intermediate position between the drive screw 2002 andthe lobe 2004. In the illustrated example, a slot 3102 is provided onthe base section 2022 of the housing 2006 to retain the bearing plate2122 a in the desired position between the screw 2002 and the lobe 2004.While not illustrated, the upper section 2024 may include acorresponding slot feature for retaining the bearing plate 2122 a in thedesired position when assembled. With this design, the lobes 2004 a,2004b become active lobes when subject to the biasing force of the lobespring 2110, and, similar to the gearbox 2100 described above, theactive lobes 2004 a,2004 b interact directly to the shaft 2104 of thedrive screw 2002 a,2002 b; however, because bearing plate 2122 a ispositioned between the lobes 2004 a,2004 b and the thread of theirrespective drive screws 2002 a,2002 b, the bearing plate 2122 aseparates the lobes 2004 a,2004 b from acting longitudinally on theirrespective drive screws 2002 a,2002 b.

FIG. 32 illustrates example operation of a drive train of the gearbox2900 of FIG. 31 . In particular, FIG. 32 illustrates how each of thelobes 2004 a,2004 b are spring loaded via the lobe springs 2110, suchthat the lobes 2004 a,2004 b are “active” rather than just beingfree-floating. In the illustrated example, the lobe springs 2110 apply aclockwise torsional spring force on the lobes 2004 a,2004 b about theirshafts 2104 as indicated by arrows 3202. The spring loaded lobes 2004a,2004 b fill any clearance in the slots 118 of the lower rails 102,thereby eliminating any fore/aft slop.

FIG. 33 is a partial cross-sectional view illustrating example operationof the gearbox 2900. With this design, the loading case with the bearingplate 2122 removes the wavy washer 2120 loading scenario described abovewith reference to FIG. 24B, thereby resulting in a true zero free-playdesign. It is possible for the gearbox 2100 to still have somelongitudinal free play. As shown in FIG. 21 , the gearbox 2100 includesan active lobe 2004 that is positioned between the drive screw 2002 andthe bearing plate 2122 a. The active lobe 2004 in this example removeslongitudinal clearance between the drive screw threads 2014 and theslots 118 of the lower rail 102; however, since the bearing plates 2122a,2022 b are fixed to the gearbox 2100 housing upper cover and lowercover 2022,2024 via engagement slots 2128 and since there may belongitudinal clearance between the drive screw 2002 and bearing plates2122 a,2022 b, this may result in longitudinal free play within thegearbox 2100. In other words, when the active lobe 2004 is positionedbetween the bearing plates 2122 a,2022 b, free play is removed betweendrive screw 2002 and lower rail slots 118, but the drive train still hasthe ability to longitudinally slide within the gearbox in an amount thatis equal to the amount of clearance between the drive screw 2002 and thebearing plates 2122 a,2022 b. Accordingly, the gearbox 2900 solves theproblem of longitudinal free play that may exist or be encounteredwithin the gearbox by positioning the bearing plate 2122 a between theactive lobe 2004 and the drive screw 2002. Anchoring the drivetrainassembly to one of the bearing plates (i.e., end plates) removesclearance between the drive screw and the lower rail slots 118 and alsoremoves clearance within the gearbox assembly that otherwise would existbetween the drive screw and bearing plates.

It is appreciated that a plurality of active lobes could be included inany position relative to the bearing plates and drive screw. An activelobe may be positioned outside of each bearing plate. An active lobe maybe positioned inside of each bearing plate. A first active lobe may bepositioned outside of a first bearing plate, and a second active lobemay be positioned inside of a second bearing plate. A first active lobemay be positioned outside of a first bearing plate, and a second activelobe may be position inside of the first bearing plate.

FIGS. 34-35 illustrate example operation of drive train within thegearbox 2900 to eliminate slop in the system. As shown in FIG. 34A,counterclockwise motor input results in clockwise rotation of the drivescrews 2002 a,2002 b as indicated by the arrow 3402, which, in thepresent example, in turn results in the upper rail 104 traveling in arearward direction along the lower rail 102. As illustrated in FIG. 34B,the rotating drive screw 2002 a,2002 b is acting on the spring 2110 atits least amount of applied moment (i.e., the moment decreases thefurther the active lobe 2004 a,2004 b cinches), and rotational drivescrew movement will always be in the direction of cinching the gapbetween active lobe 2004 and the slots 118 of the lower rail 102,thereby adding frictional drag into the system. However, the system willnot bind as the wavy washer 2118 within the system will compressallowing the screws 2002 to continue their traverse. With reference toFIGS. 35A and 35B, clockwise motor input through the shaft results inthe drive screws 2002 a,2002 b rotating counter-clockwise, as indicatedby arrow 3502 and the upper rail 104 traversing forward relative to thelower rail 102. As illustrated in FIG. 35B, the rotating drive screw2002 a,2002 b is acting on the spring 2110 at its least amount ofapplied moment (e.g., the moment decreases the further the active lobe2004 a,2004 b cinches), and the rotational drive screw movement willopen up the gap between active lobe 2004 a,2004 b and the slot 118 wallof the lower rail 102 allowing system to move with little drag.

Therefore, the disclosed systems and methods are well adapted to attainthe ends and advantages mentioned as well as those that are inherenttherein. The particular embodiments disclosed above are illustrativeonly, as the teachings of the present disclosure may be modified andpracticed in different but equivalent manners apparent to those skilledin the art having the benefit of this disclosure. Furthermore, nolimitations are intended to the details of construction or design shown,other than as described in the claims below. It is therefore evidentthat the particular illustrative embodiments disclosed above may bealtered, combined, or modified and all such variations are consideredwithin the scope of the present disclosure. The systems and methodsillustratively disclosed may be practiced in the absence of any elementthat is not specifically disclosed herein and/or any optional elementdisclosed herein. The terms in the claims have their plain, ordinarymeaning unless otherwise explicitly and clearly defined by the patentee.All numeric values provided in the specification are for the specificembodiment described and may be varied as appropriate for a givenapplication. The indefinite articles “a” or “an,” as used in the claims,mean one or more than one of the elements that it introduces. If thereis any conflict in the usages of a word or term in this specificationand one or more patent or other documents that may be incorporatedherein by reference, the definitions that are consistent with thisspecification should be adopted.

The use of directional terms such as above, below, upper, lower, upward,downward, left, right, and the like are used in relation to theillustrative embodiments as they are depicted in the figures, the upwardor upper direction being toward the top of the corresponding figure andthe downward or lower direction being toward the bottom of thecorresponding figure.

As used herein, the phrase “at least one of” preceding a series ofitems, with the terms “and” or “or” to separate any of the items,modifies the list as a whole, rather than each member of the list (i.e.,each item). The phrase “at least one of” allows a meaning that includesat least one of any one of the items, and/or at least one of anycombination of the items, and/or at least one of each of the items. Byway of example, the phrases “at least one of A, B, and C” or “at leastone of A, B, or C” each refer to only A, only B, or only C; anycombination of A, B, and C; and/or at least one of each of A, B, and C.

1-74. (canceled)
 75. A seat rail assembly comprising: a first railhaving longitudinally spaced slots; and a second rail having a gear box,the gear box having: at least one drive screw rotatable in a first orsecond rotational direction, each drive screw having a shaft and athread configured to engage with the longitudinally spaced slots of thefirst rail; a lobe provided on the shaft of the drive screw andconfigured to engage with the longitudinally spaced slots of the firstrail, wherein the lobe is freely rotatable relative to the thread of thedrive screw; and a lobe spring configured to bias the lobe in the firstrotational direction.
 76. The seat rail assembly of claim 75, whereinthe first rail defines a sliding space between the longitudinally spacedslots.
 77. The seat rail assembly of claim 75, wherein the second railis at least partially providing within the sliding space of the firstrail.
 78. The seat rail assembly of claim 75, wherein the lobe has alimited range of rotation about the shaft.
 79. The seat rail assembly ofclaim 75, wherein the lobe includes a thread that is continuous with thethread of the drive screw.
 80. The seat rail assembly of claim 75,wherein the lobe includes a thread, and the thread of the lobe and thethread of the drive screw have an equal pitch.
 81. The seat railassembly of claim 75, wherein the gearbox includes at least one bearingplate that rotatably supports the shaft of the drive screw.
 82. The seatrail assembly of claim 81, wherein the bearing plate is positionedbetween the thread of the drive screw and the lobe.
 83. The seat railassembly of claim 81, wherein the lobe is positioned between the threadof the drive screw and the bearing plate.
 84. The seat rail assembly ofclaim 75, wherein the second rail includes a second gear box, the secondgear box comprising: at least one drive screw rotatable in a first orsecond rotational direction, each drive screw having a shaft and athread configured to engage with the longitudinally spaced slots of thefirst rail; a lobe provided on the shaft of the drive screw andconfigured to engage with the longitudinally spaced slots of the firstrail, wherein the lobe is freely rotatable relative to the thread of thedrive screw; and a lobe spring configured to bias the lobe in the firstrotational direction.
 85. The seat rail assembly of claim 84, whereinthe second gearbox includes at least one bearing plate that rotatablysupports the shaft of the drive screw.
 86. The seat rail assembly ofclaim 84, wherein the bearing plate of the second gearbox is positionedbetween the thread of the drive screw and the lobe thereof.
 87. The seatrail assembly of claim 84, wherein the lobe of the second gear box ispositioned between the thread of the drive screw and the bearing plateof the second gear box.
 88. The seat rail assembly of claim 75, whereinthe lobe has a bore within which the shaft of the drive screw isreceived, the shaft of the drive screw includes a flat feature, and apair of angled flat surfaces are formed in the bore of the lobe andwherein the lobe is rotatable relative to the shaft between a firstposition, where a first of the pair of angled flat surfaces abuts theflat feature, and a second position, where a second of the pair ofangled flat surfaces abuts the flat feature.
 89. A seat rail assemblyfor mounting a vehicle seat to a vehicle floor, comprising: a first railconfigured to be mounted to a vehicle floor, the lower first rail havinglongitudinally spaced slots and defining a sliding space; a second railconfigured to receive at least one vehicle seat mounted thereon, thesecond rail at least partially provided within the sliding space of thefirst rail and slidable relative to the lower rail in a first directionor in a second direction opposite the first direction; a gear boxprovided on the second rail, the gear box comprising: at least one drivescrew rotatable in a first or second rotational direction, each drivescrew having a shaft and a thread configured to engage with thelongitudinally spaced slots of the first rail, a lobe provided on theshaft of the drive screw configured to engage with the longitudinallyspaced slots of the first rail, wherein the lobe is freely rotatablerelative to the thread of the drive screw, and a lobe spring configuredto bias the lobe in the first rotational direction; an engagementassembly provided within the sliding space of the first rail, theengagement assembly comprising a first engagement member and a secondengagement member that are configured to move independently of eachother depending on movement of the second rail relative to the firstrail, the first engagement member slidably provided on the second rail,the second engagement member slidably provided on the first engagementmember and slidable between a first position and a second position;wherein the first engagement member is biased in the first direction andthe second engagement member is biased in the second direction towardsthe first position; and wherein, as the second rail slides relative tothe first rail in response to operation of the gear box, the secondengagement member maintains contact with the first rail and the firstengagement member maintains contact with the second rail.
 90. The seatrail assembly of claim 89, wherein the gearbox includes at least onebearing plate that rotatably supports the shaft of the drive screw. 91.The seat rail assembly of claim 90, wherein the bearing plate ispositioned between the thread of the drive screw and the lobe.
 92. Theseat rail assembly of claim 90, wherein the lobe is positioned betweenthe thread of the drive screw and the bearing plate.